Yes, the PIN is configured correctly.
Tha sam code (pin and usart name is changed) is working with USART2.
The interesting thing is that i use USART2, after the PIO init the RTS goes LOW, when USART1 RTS goes high, this is before init of the USARTs

Dear all,
I have a project using STM32F103CBT6.
I have a problem with the USART1 HW flow control.
When i set RTS mode the pin is never go low (indicate that it can accept data). If i set to none flow control it works well.

I try to use the sample project (hyperterminal HW flow control), it works fine with USART2, but if i put the code to USART1 it's not.
I really have to use USART1, just that modul support 3Mbaud.

Not sure if you got resolution on this, but I've been seeing this exact same problem on an STM32R103RET6 part (Z Rev), and got here from Googling the issue.

Everything is enabled correctly, and in fact the RTS pin works with my attached wireless modem if I use the pin as a GPIO instead. If USART1 is in control, the RTS pin goes high by default, causing me problems.